Custom configured golf shaft

ABSTRACT

A golf shaft assembly is a stand-alone component for subsequent use with a golf club-head. The assembly includes a shaft with an adapter that is affixed to the bottom end of the shaft for engaging with the club-head. An adapter-spline is formed near the top end of the adapter that meshes with a club-head spline on the hosel of a club-head to hold the club-head in a base position relative to the golf shaft. In this base position the club-head has a predetermined loft angle α and a predetermined face angle β that are presented preparatory to a golf swing by a golfer. Optionally, the assembly can include at least one annular shaped collar that can be positioned between the adapter-spline and the club-head spline for introducing loft and/or club-face adjustments to optimize the user&#39;s golf swing.

FIELD OF THE INVENTION

The present invention pertains generally to stand alone golf shafts that can be purchased as a separate golf club component. More particularly, the present invention pertains to golf shafts with adapters that engage the golf shaft with a golf club-head to thereby create a customized golf club configuration for the user. The present invention is particularly, but not exclusively, useful as a golf club shaft with an adapter that allows for predetermined loft and/or club-face adjustments that will optimize a user's golf swing.

BACKGROUND OF THE INVENTION

When a golf shaft is considered as a separate component of a golf club, several considerations must appreciated before the shaft is affixed to a club-head. For one, the flex of a shift, i.e. its ability to bend, will affect both the direction and distance of an in-flight golf ball. For another, during a golf swing, the orientation of the club-face at the time of impact with the golf ball is of particular importance. Both of these considerations are interrelated.

Insofar as the flex of a golf shaft is concerned, it is a permanent characteristic of the shaft that is introduced during the manufacture of a golf shaft. As such, it must be accounted for during the assembly of a golf club. More specifically, in the manufacture of a hollow golf shaft, the line where edges of a metal strip are joined together to create the shaft is known as a spine. For a hollow shaft made of a composite material, a spine can be designed into the shaft. In either case this spine extends along the entire length of the shaft, and it effectively determines the plane in which an optimal bending ability for the shaft is established.

When a golf shaft is joined with a club-head, the relationship between them becomes fixed. However, the club-face orientation relative to a golf ball at the time of its impact with a golf ball is totally within the control of the golfer. Thus, together, golf shaft flex and club-face orientation are features that greatly influence the performance of the golf club when hitting a golf ball during a golf swing. Of particular importance in this regard is the club-face plane and the club-face line of a club-head at the time of impact.

All golf clubs define a club-face plane that is specifically designed to launch a golf ball onto a trajectory along an intended, in-flight target line following a perfect (emphasis added) golf swing. The initial elevation angle of a golf ball trajectory at launch is influenced by the angle between the club-face plane and a vertical plane. This is a manufactured characteristic of a golf club-head and is known as the club-head's loft angle.

The club-face line, which is located in the club-face plane, is used to measure the club-head's azimuth angle relative to the target line of the golf ball's trajectory mentioned above. This angle is commonly referred to as the face angle. For a perfectly addressed golf ball (i.e. prior to swinging the golf club) the face angle will preferably be 90°. Thus, in summary, when a golfer properly addresses a golf ball, the club-head of the golf club will present a predetermined loft angle that was established for the club during its manufacture. Also, the golfer will establish a face angle for the club-head that is equal to 90°, i.e. perpendicular to the intended, in-flight target line.

It happens however, even though a golf ball has been properly addressed, perfection is rarely maintained once a golf swing begins. In reality, for any of several reasons the loft angle and/or the face angle of the club-face will have changed by the time the golf club-head makes contact with the golf ball. Unfortunately for many golfers, this situation is a chronic condition.

In light of the above, it is an object of the present invention to provide a golf shaft assembly that can be purchased as a stand-alone product, separately from a golf club-head, to be subsequently engaged with the golf club-head. Another object of the present invention is to provide a golf shaft assembly which can individually or collectively adjust the loft angle of a golf club and the club-face angle of a golf club when the golf shaft assembly is joined with a golf club-head. Still another object of the present invention is to provide a golf shaft assembly that is easy to manufacture, is simple to use and is comparatively cost effective.

SUMMARY OF THE INVENTION

In accordance with the present invention, a golf shaft assembly includes, in combination, a golf shaft and an adapter. For this combination the golf shaft has a predetermined length with a first end and a second end. The golf shaft also defines an axis and it is formed with an axially oriented spine that defines a base line for the shaft relative to a plane of predetermined bending resistance for the shaft. Also included is a handle that is fastened to the first end of the shaft and an elongated adapter that is affixed to the second end of the shaft. When they are joined together, the adapter is aligned with the axis of the shaft relative to a reference mark that has been pre-located on the shaft. Importantly, the reference mark on the shaft is positioned at a predetermined angular orientation relative to the base line of the shaft to optimize its bending resistance.

Structurally, the adapter includes a sleeve that defines an axis, and has a first end and a second end wherein the first end of the sleeve is adapted to be affixed to the second end of the shaft. Further, the sleeve is formed with an annular shaped adapter-spline which is centered on the axis of the sleeve adjacent its first end. For the present invention, the purpose of the adapter is to interconnect the shaft assembly with the hosel of a golf club-head.

For its use with a first embodiment of the present invention, the hosel of a golf club-head is formed with an annular shaped club-head spline that is specifically dimensioned to engage with the adapter-spline of the adapter. For this embodiment of the present invention, the hosel of the club-head is attached to the second end of the sleeve to hold the club-head on the golf shaft in a base position relative to the shaft reference mark. In particular, this is accomplished by a direct engagement of the adapter-spline on the adapter with the club-head spline on the hosel of the club-head. With this engagement, a predetermined loft angle α is established (wherein the loft angle α is designed by the club-head manufacturer), and a predetermined face angle β can be established by the golfer (wherein face angle β is 90°) preparatory to a perfect golf swing by the golfer. Accordingly, for this embodiment of the present invention, no variation in either α or β is anticipated.

For another embodiment of the present invention, an adjustable adapter is provided with the ability to adjust the loft angle α, and/or the face angle β of a club-head. Specifically, these adjustments will reorient the club-head on the golf shaft relative to its base position as desired to provide consistency for a golfer's swing.

In accordance with the present invention, an adjustable adapter requires a washer that is positioned on the sleeve and oriented around the sleeve's axis adjacent its second end. A first annular shaped collar is positioned on the sleeve between the adapter-spline and the washer. This first collar is centered on the axis of the sleeve and it has an upper spline that is formed for engagement with the adapter-spline of the adapter. The first collar also has a lower spline. Additionally, an optional second annular shaped collar is positioned on the sleeve between the first collar and the washer. It too is centered on the axis of the sleeve. Further, the second collar has an upper spline that is formed for engagement with the lower spline of the first collar, and it has a lower spline that is formed for engagement with the club-head spline.

As intended for the present invention, an adjustable adapter for a golf shaft assembly can be configured to reposition the club-head on the shaft relative to the base position described above in a preferred orientation. In particular, adjustments of the adapter are incorporated by respectively rotating the first and/or the second collar around the sleeve and into preselected orientations on the adapter. Based on the engaged relationship of the first and second collars relative to each other, and the engagements of the first and second collars respectively to the adapter-spline and the club-head spline, loft angle changes Δα can be established in a range where Δα is less than +5°. Similarly, based on the same relationship, the adjustable adapter can provide for face angle changes Δβ that are in a range where Δβ is less than ±10°.

For an attachment of the golf shaft assembly with a club-head, the golf club-head needs to be formed with a tubular shaped channel that passes centrally through the club-head spline of the golf head. Further, it is necessary for the sleeve of the adapter to be formed with a threaded recess that is formed into the second end of the sleeve along the axis of the sleeve. Thus, for either embodiment of the adapter disclosed, the adapter-spline can be engaged with the club-head spline when a screw is extended through the channel in the club-head and engaged with the threaded recess of the sleeve. With an adapter having no adjustment collars, a tightening of the screw will then hold the club-head on the shaft in the base position with the club-head spline engaged directly with the adapter-spline. On the other hand, with an adjustable adapter, the adapter-spline can be engaged with the club-head spline via the first and second annular shaped collars to introduce desired variation in the loft angle α and the face angle β of the club-head.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of this invention, as well as the invention itself, both as to its structure and its operation, will be best understood from the accompanying drawings, taken in conjunction with the accompanying description, in which similar reference characters refer to similar parts, and in which:

FIG. 1 is an exploded perspective view of a golf club showing the shaft assembly of the present invention in its relationship with a golf club-head;

FIG. 2 is an enlarged perspective view of an adjustable adapter in accordance with the present invention;

FIG. 3 is an elevation view of a golf club-head as seen in the direction of arrow 3 presented in FIG. 1 for the purpose of defining a loft angle α for the club-head; and

FIG. 4 is a top plan view of the golf club-head shown in FIG. 3, as seen in the direction of arrow 4 presented in FIG. 1 for the purpose of defining a face angle β for the club-head.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to FIG. 1 a shaft assembly in accordance with the present invention is shown and is generally designated 10. As shown, the shaft assembly 10 includes a shaft 12 with an adapter 14 positioned at one end of the shaft 12 and a handle 16 positioned at its other end. As intended for the present invention, both the adapter 14 and the handle 16 are respectively affixed to the shaft 12 to create the shaft assembly 10.

Still referring to FIG. 1 it is to be appreciated that the purpose of the present invention is to provide a shaft assembly 10 that can be separately purchased and then subsequently engaged with a particularly selected golf club-head 18. For this purpose, it is envisioned that the golf club-head 18 will be formed with a hosel 20 and it will have a club-face 22.

An important consideration for the present invention is the proper alignment of the shaft 12 with the adapter 14. Specifically, in accordance with disclosure presented in greater detail below, the adapter 14 will provide for a predetermined alignment of the shaft 12 with the club-head 18. The adapter 14, however, may be adjusted to provide for several different alignment configurations. Thus, it is necessary to establish a reference alignment between the adapter 14 and the shaft 12. In particular, an alignment of the adapter 14 with the shaft 12 is necessary to properly orient the spine of the shaft 12 relative to the adapter 14, and thereby optimize the performance of the shaft 12 during a golf swing. This reference alignment is established by aligning a reference mark 24 on the shaft 12 with a reference mark 26 on the adapter 14. Accordingly, subsequent reconfigurations of the adapter 14 will always be based on the reference alignment.

As shown in FIG. 2, the adapter 14 includes an elongated, cylindrical-shaped sleeve 28 that defines an axis 30. An adapter-spline 32 is formed at one end of the sleeve 28 and it is radially oriented around the axis 30.

Additionally, a threaded recess 34 is formed longitudinally into the sleeve 28 along the axis 30 at the other end of the sleeve 28. Also, a washer 36 is positioned adjacent the end of the sleeve 28 to surround the threaded recess 34, as shown. For its combination with the shaft 12, the adapter-spline of the adapter 12 is fixedly attached to the shaft 12.

Still referring to FIG. 2 an adjustable adapter 14 for the present invention preferably includes a first annular shaped collar 38 that is centered on the axis 30 of the sleeve 28 and positioned thereon between the adapter-spline 32 and the washer 36. The first collar 38 has an upper spline 40 that is formed for engagement with the adapter-spline 32, and it has a lower spline 42. The adjustable first collar 38 also includes a second annular shaped collar 44 that, like the first collar 38, is centered on the axis 30 of the sleeve 28. Further, as shown, a second adjustable collar 44 is positioned on the sleeve 28 between the first collar 38 and the washer 36. The second collar 44 has an upper spline 46 that is formed for engagement with the lower spline 42 of the first collar 38, and it has a lower spline 48 which is formed for engagement with the club-head spline 50 that is formed on the hosel 20 of the club-head 18.

With reference to FIG. 3 it will be appreciated that the club-face 22 of the club-head 18 will define a club-face plane 52 (shown perpendicular to the plane of FIG. 3) that will intersect a vertical plane 54 (also shown perpendicular to the plane of FIG. 3). In their relationship with each other, the club-face plane 52 and the vertical plane 54 establish a loft angle α that is measured between the two (i.e. between the vertical plane 54 and the club-face plane 52). This loft angle α is a manufacturing design for the club-head 18 that is predetermined for a perfect swing.

Referring to FIG. 4, it will also be appreciated that in addition to the loft angle α of the club-face 22, a proper golf swing must also consider a face angle β. In order to determine the face angle β it is first necessary to define a horizontal club-face line 56. The face angle β can then be determined relative to an intended target line 58 for the golf shot (i.e. the direction in which the golfer intends to hit a golf ball). Thus, it is common practice to refer to the face angle β as being the angle measured between the club-face line 56 and a line 60 perpendicular to the target line 58. Preferably, the face angle β will be zero degrees. Variations from β=0°, however, are entirely within the control of the golfer and will almost invariably result in an errant golf shot.

An engagement of the shaft assembly 10 with a golf club-head 18 is accomplished by passing a screw (not shown) through a tubular shaped channel formed through the hosel 20 of the club-head 18. This action will also center the end of the screw inside the club-head spline 50. Further, the screw will be extended from the club-head 18 for engagement with the threaded recess 34 of the sleeve 28 to engage the club-head spline 50 with the adapter 14. The consequence here is to hold the club-head 18 on the shaft 12 with a predetermined loft angle α, and a corrective face angle β.

As intended for the present invention, for one embodiment of the adapter 14, the adapter 14 can be directly engaged with the club-head spline 50. In another embodiment, the adapter 14 can be preconfigured by respectively rotating the first collar 38 and/or the second collar 44 in a manner that provides for a fixed repositioning of the club-head 18 relative to the base position. Specifically, with an adjustable adapter 14 a loft angle change Δα can be made in a range where Δα is less than ±5°. Also, a face angle change Δβ can be made in a range where Δβ is less than ±10°.

While the particular Custom Configured Golf Shaft as herein shown and disclosed in detail is fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that it is merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims. 

1-4. (canceled)
 5. The golf shaft assembly of claim 21 wherein the golf club-head is formed with a tubular shaped channel passing through the club-head spline, wherein the sleeve has a threaded recess formed into the second end of the sleeve along the axis of the sleeve, and further wherein a screw extends through the channel in the club-head for engagement with the threaded recess of the sleeve to hold the club-head on the shaft with the club-head spline engaged with the adapter-spline.
 6. The golf shaft assembly of claim 21 wherein the club-head has a club-face defining a club-face plane, and wherein the loft angle α is measured between a vertical plane and the club-face plane.
 7. The golf shaft assembly of claim 6 wherein the club-face defines a club-face line and the face angle β is measured between the club-face line and a line perpendicular to a target line.
 8. The golf shaft assembly of claim 7 wherein an engagement of the club-head spline with the adapter-spline provides for fixed repositioning of the club-head relative to the base position with a loft angle change Δα in a range where Δα is less than ±5° and with a line angle change Δβ in a range where Δβ is less than ±10°.
 9. (canceled)
 10. (canceled)
 11. A golf shaft assembly adapted for engagement with a golf club-head to provide the golf club-head with predetermined adjustments for a club-face loft angle α and a club-face line angle β, wherein the golf club-head has a hosel formed with an annular shaped club-head spline, and wherein the golf shaft assembly comprises: a shaft having a predetermined length, wherein the shaft has a first end and a second end and defines an axis; a handle fastened to the first end of the shaft; and an adapter having a sleeve defining an axis and having a first end and a second end, wherein the first end of the sleeve is adapted to be affixed to the second end of the shaft.
 12. The golf shaft assembly of claim 11 wherein the adapter comprises: an annular shaped adapter-spline formed on the sleeve adjacent the first end thereof, wherein the adapter-spline is centered on the axis of the sleeve; an annular shaped club-head spline formed on the hosel of the golf club-head, wherein the club-head spline is formed to engage with the adapter-spline to present a predetermined loft angle α and a predetermined face angle β for the club-head preparatory to a golf swing by a golfer; a first annular shaped collar centered on the axis of the sleeve and positioned thereon, wherein the first collar has an upper spline formed for engagement with the adapter-spline and the first collar has a lower spline; and a second annular shaped collar centered on the axis of the sleeve and positioned thereon, wherein the second collar has an upper spline formed for engagement with the lower spline of the first collar and the second collar has a lower spline formed for engagement with the club-head spline, and wherein the upper spline of the first collar is formed with a spline pitch to impart a loft angle change Δα for the club-head relative to a base position, and wherein the lower spline of the second collar is formed with an angular offset to impart a line angle change Δβ relative to the base position.
 13. (canceled)
 14. The golf shaft assembly of claim 12 wherein the shaft is formed with an axially oriented spine to define a base line for the shaft relative to a plane of predetermined bending resistance for the shaft and wherein the shaft includes a shaft reference mark positioned on the shaft at a predetermined angular orientation relative to the base line of the shaft and the adapter is aligned with the axis of the shaft, and wherein the club-head is selectively oriented by the first collar of the adapter with a loft angle change Δα in a range less than ±5° relative to the base position and the club-head is selectively oriented by the second collar of the adapter with a line angle change Δβ in a range less than ±10° relative to the base position.
 15. The golf shaft assembly of claim 12 wherein the golf club-head is formed with a tubular shaped channel passing through the club-head spline, and the sleeve further comprises a threaded recess formed into the second end of the sleeve along the axis of the sleeve adapted to receive a screw extending through the channel in the club-head for engagement with the threaded recess of the sleeve to hold the club-head on the shaft with the club-head spline engaged with the adapter-spline.
 16. A method for manufacturing a golf shaft assembly which comprises the steps of: forming a shaft having a predetermined length with a first end and a second end to define an axis therebetween, wherein the shaft is formed with an axially oriented spine to define a base line for the shaft relative to a plane of predetermined bending resistance for the shaft; fastening a handle to the first end of the shaft; and affixing an adapter to the second end of the shaft.
 17. The method of claim 16 further comprising the steps of: creating a sleeve defining an axis and having a first end and a second end, wherein the first end of the sleeve is adapted to be affixed to the second end of the shaft; forming an annular shaped adapter-spline on the sleeve adjacent the first end thereof, wherein the adapter-spline is centered on the axis of the sleeve; placing a washer around the axis on the sleeve adjacent the second end thereof; positioning a first annular shaped collar centered on the axis of the sleeve between the adapter-spline and the washer, wherein the first collar has an upper spline formed for engagement with the adapter-spline and the first collar has a lower spline; and positioning a second annular shaped collar centered on the axis of the sleeve between the first collar and the washer, wherein the second collar has an upper spline formed for engagement with the lower spline of the first collar and the second collar has a lower spline.
 18. The method of claim 17 further comprising the steps of: providing a golf club-head having a hosel with a club-head spline formed for engagement with the lower spline of the second collar, and having a tubular shaped channel passing through the club-head and the club-head spline; creating a threaded recess into the second end of the sleeve along the axis of the sleeve; and extending a screw through the channel in the club-head for engagement with the threaded recess of the sleeve to hold the club-head on the shaft with the club-head spline engaged with the lower spline of the second collar to present a predetermined loft angle α and a predetermined face angle β for the club-head preparatory to a golf swing by a golfer.
 19. The method of claim 18 further comprising the steps of: forming the upper spline of the first collar with a spline pitch to impart a loft angle change Δα for the club-head relative to a base position; and forming the lower spline of the second collar with an angular offset to impart a face angle change Δβ relative to the base position.
 20. The method of claim 19 wherein the spline pitch of the first collar imparts a loft angle change Δα for the club-head in a range less than ±5° relative to the base position, and wherein the angular offset of the second collar of the adapter imparts a face angle change Δβ in a range less than ±10° relative to the base position.
 21. A golf shaft assembly adapted for engagement with a golf club-head to provide the golf club-head with predetermined adjustments for a club-face loft angle α and a club-face line angle β, wherein the golf club-head has a hosel formed with an annular shaped club-head spline, and wherein the golf shaft assembly comprises: a shaft having a predetermined length, wherein the shaft has a first end and a second end and defines an axis; a handle fastened to the first end of the shaft; an elongated adapter including a sleeve having a first end and a second end with the first end of the sleeve affixed to the second end of the shaft with the sleeve aligned along the axis of the shaft; an annular shaped adapter-spline formed on the sleeve adjacent the first end thereof, wherein the adapter-spline is centered on the axis of the sleeve; a first annular shaped collar centered on the axis of the sleeve and selectively positioned thereon adjacent the adapter-spline, wherein the first collar has an upper spline formed for selective engagement with the adapter-spline, and the first collar has a lower spline; and a second annular shaped collar centered on the axis of the sleeve and positioned thereon adjacent the first collar and opposite the adapter spline, wherein the second collar has an upper spline formed for selective engagement with the lower spline of the first collar and the second collar has a lower spline formed for engagement with the club-head spline, wherein the engagement of the first collar with the adapter spline adjusts the club-face loft angle α, and the engagement of the second collar with the first collar adjusts the club-face line angle β when the shaft assembly is engaged with the golf club-head.
 22. The golf shaft assembly of claim 21 wherein the upper spline of the first collar is formed with a spline pitch to impart a loft angle change Δα for the club-head relative to a base position, and wherein the lower spline of the second collar is formed with an angular offset to impart a line angle change Δβ relative to the base position.
 23. The golf shaft assembly of claim 22 wherein the club-head is selectively oriented by the first collar of the adapter with a loft angle change Δα in a range less than ±5° relative to the base position and the club-head is selectively oriented by the second collar of the adapter with a line angle change Δβ in a range less than ±10° relative to the base position.
 24. The golf shaft assembly of claim 22 wherein the shaft is formed with an axially oriented spine to define a base line for the shaft relative to a plane of predetermined bending resistance for the shaft and the shaft has a reference mark positioned thereon at a predetermined angular orientation relative to the base line of the shaft
 25. The golf shaft assembly of claim 24 wherein the adapter spline has a reference mark positioned thereon for alignment with the reference mark on the shaft to establish a reference alignment between the adapter and the shaft. 